35) Solubility Test for Asphalt Materials

Solubility Test for Asphalt Materials Introduction:

This test method covers the determination of the degree of solubility in trichloroethylene of  asphalt materials having little or no mineral matter. The portion that is soluble in trichloroethylene represents the active cementing constituents. Objectives:

Objective of this test is to determine the degree of solubility in trichloroethylene of asphalt materials having little or no mineral matter. Apparatus:

The following apparatus are required (Figure 1). 1) ooch !rucib !rucible le " gla#ed inside inside and outside outside with the the e$ception e$ception of outside outside bottom surface. surface. The appro$imate dimensions shall be a diameter of %% mm at the top& tapering to ' mm at the bottom& and a depth of % " * mm. ) lass lass Fibe Fiberr +ad +ad " '. '. cm. cm. ') Filter Flas, Flas, " heavy heavy wall& wall& with side side tube& - - or - - ml capacity capacity.. %) Filter Tube Tube " % to % mm mm inside inside diameter diameter.. -) /ubber /ubber Tubing Tubing or 0dapter 0dapter " for holding holding the the ooch crucible crucible on the the filter tube. tube. ) rlen rlenme meye yerr flas, flas, " 11- ml. ml. 2) Oven " capable capable of maintain maintaining ing a temperat temperature ure of 11 11 3 - !.

Figure 1 " 4olubility Test 0pparatus.

Procedure:

4ample +reparation 1) The ooch crucible plus one thic,ness of the glass fiber pad was placed in an oven at 11 3 - ! for 1- min& was allowed to cool in a desiccator& and then the mass was determined to the nearest .1 mg. This mass was designated as 506. The desiccator was stored in until ready for use. ) 7f the sample was not fluid& it was heated to any convenient temperature& but in any case not more than 111 ! above the softening point. 8ormally the temperature at which this test is run is not critical& and it may be performed at the laboratory air temperature. For  referee tests& however& the flas, and sample in solution shall be placed in a water bath maintained at '2.* 3 .'  ! for 1 hour before filtering. Test +rocedure 1) 0ppro$imately  g of the sample was transferred into a tarred 1- ml rlenmeyer flas, or  other suitable container. ) The sample was allowed to cool to ambient temperature and then determined the mass to the nearest 1 mg. This mass was designated as 596. ') 1 ml of the trichloroethylene was added to the container in small portions with continuous agitation until all lumps disappeared and no un:dissolved sample adhered to the container. %) The flas, was stopper or otherwise the container was covered and set aside for at least 1min. -) The previously prepared and weighed ooch crucible was placed in the filtering tube. ) The glass fiber pad was wetted with a small portion of trichloroethylene and the solution was decanted through the glass fiber pad of the crucible with or without light suction as may be necessary. 2) ;hen the insoluble matter was appreciable& retained as much of it as possible in the container until the solution had drained through the mat. *) The container was washed with a small amount of solvent and& using a stream of solvent from a wash bottle& all insoluble matter was transferred to the crucible. <) The insoluble matter in the crucible was washed with solvent until the filtrate was substantially colorless& then strong suction was applied to remove the remaining solvent. 1) The crucible was removed from the tube& the bottom was washed free of any dissolved matter& and the crucible was placed on top of an oven or on a steam bath until all odor of  the trichloroethylene was removed. 11) The crucible was placed in an oven at 11 3 - ! for at least  min. 1) The crucible was cooled in a desiccator for ' 3 - min and its mass was determined to the nearest .1 mg. 1') The drying and weighing was repeated until constant mass (3 .' mg) was obtained. This mass was designated as 5!6.

Observation:

0 = mass of crucible and filter = 12.'* g 9 = mass of sample

= .1- g

! = mass of crucible& filter and insoluble material = 12.'< g Calculations and result:

> 7nsoluble = ! " 0 $ 1 9 > 4oluble = 9 " (! " 0) $ 1 9 ;here? 0 = mass of crucible and filter  9 = mass of sample ! = mass of crucible& filter and insoluble material (For percentages of insoluble less than 1.& report to the nearest .1 >. For percentages of  insoluble 1. or more& report to the nearest .1 >) Specimen Calculation:

> 7nsoluble = 12.'< " 12.'*   .1-

$ 1

 = 0!" # > 4oluble = .1- " (12.'< " 12.'*)   .1 = $$%& #

$ 1

'iscussion: () *hat is the importance of the solubility value of a bitumen sample+

0sphalt cements which use for @A0 paving& should consist of almost pure bitumen. 7mpurities are not actively cementing constituents and may be detrimental to asphalt cement performance. Aineral impurities can be quantified by the solubility test. Ainimum solubility of <<> is specified in highway specifications. Bnowing solubility values& one can determine the purity of the asphalt cement which is being used relative to the specification values ensuring undesirable materials are not blended into the product. ,) *hat are the other methods available to find the solubility of bitumen+ •

4olubility in carbon disulfide 0sphalt consists primarily of bitumens which are high:molecular: weight hydrocarbons soluble in !4. The bitumen material is measured by means of its solubility in !4& 04TA C%.

•

4olubility in trichloroethylene Cue to e$treme flammability of !4& solubility in trichloroethylene is specify in asphalt cement specifications. 04TA C %.

•

4olubility in n:+ropyl 9romide 0s the trichloroethylene has identified as a carcinogen and contribute to the depletion of  the earthDs o#one layer& solubility in n:+ropyl 9romide has introduced by 04TA. 04TA C 2--'.

&) *hat is the purpose of doin- a solubility test+

The purpose of the doing a solubility test is to detect contaminations in asphault cement to complied with specifications. !) *hat are the modifications can propose to the solubility test+

7t is better to use different solution since the trichloroethylene has identified as a carcinogen and contribute to the depletion of the earthDs o#one layer.